Real-time RT-PCR analysis of mRNA decay: half-life of Beta-actin mRNA in human leukemia CCRF-CEM and Nalm-6 cell lines

BACKGROUND: We describe an alternative method to determine mRNA half-life (t(1/2)) based on the Real-Time RT-PCR procedure. This approach was evaluated by using the β-actin gene as a reference molecule for measuring of mRNA stability. RESULTS: Human leukemia Nalm-6 and CCRF-CEM cells were treated with various concentrations of Actinomycin D to block transcription and aliquots were removed periodically. Total RNA was isolated and quantified using the RiboGreen(®) fluorescent dye with the VersaFluor Fluorometer System. One μg of total RNA was reverse transcribed and used as template for the amplification of a region of the β-actin gene (231 bp). To generate the standard curve, serial ten-fold dilutions of the pBactin-231 vector containing the cDNA amplified fragment were employed, β-actin mRNAs were quantified by Real-Time RT-PCR using the SYBR(®) Green I fluorogenic dye and data analyzed using the iCycle iQ system software. Using this method, the β-actin mRNA exhibited a half-life of 6.6 h and 13.5 h in Nalm-6 and CCRF-CEM cells, respectively. The t(1/2) value obtained for Nalm-6 is comparable to those estimated from Northern blot studies, using normal human leukocytes (5.5 h). CONCLUSIONS: We have developed a rapid, sensitive, and reliable method based on Real-Time RT-PCR for measuring mRNA half-life. Our results confirm that β-actin mRNA half-life can be affected by the cellular growth rate

On dual canonical bases

The dual basis of the canonical basis of the modified quantized enveloping algebra is studied, in particular for type $A$. The construction of a basis for the coordinate algebra of the $n\times n$ quantum matrices is appropriate for the study the multiplicative property. It is shown that this basis is invariant under multiplication by certain quantum minors including the quantum determinant. Then a basis of quantum SL(n) is obtained by setting the quantum determinant to one. This basis turns out to be equivalent to the dual canonical basis

Feasibility and Accessibility of a Tailored Intervention for Informal Caregivers of People with Severe Psychiatric Disorders: a Pilot Study

Objectives: This study aimed to assess the acceptability and feasibility of a new tailored intervention for informal caregivers: the Ensemble (Together) program. Methods: An open pre–post within-subject comparison pilot study was conducted. Twenty-one informal caregivers completed the five-session Ensemble program. Two measurement tools were used: The Brief Symptom Inventory (BSI) and the Life Orientation Scale (LOT-R). Results: The results showed that informal caregivers were in need of individual support and were ready to participate in the Ensemble program independent of the patient’s diagnosis or stage of illness. The participants were very satisfied, and 95.4% completed the program. The preliminary results also showed that in five sessions, informal caregivers’ Global Severity Index measured by the BSI and their optimism about their future (measured by the LOT-R) were significantly improved. Conclusion: This pilot study provided preliminary results concerning the feasibility and acceptability of the tailored Ensemble program and indicates the need for a randomized trial. The Ensemble program is appropriate for both the acute and chronic phases of disease. Individualized brief and useful interventions for informal caregivers may provide more positive outcomes in care

Cytotoxic effect of 5-aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR) on childhood acute lymphoblastic leukemia (ALL) cells: implication for targeted therapy

Acute lymphoblastic leukemia (ALL) is the most common hematological malignancy affecting children. Despite significant progress and success in the treatment of ALL, a significant number of children continue to relapse and for them, outcome remains poor. Therefore, the search for novel therapeutic approaches is warranted. The aim of this study was to investigate the AMP activated protein kinase (AMPK) as a potential target in childhood acute lymphoblastic leukemia (ALL) subtypes characterized by non-random translocation signature profiles. We evaluated the effects of the AMPK activator AICAR on cell growth, cell cycle regulators and apoptosis of various childhood ALL cells. We found that treatment with AICAR inhibited cell proliferation, induced cell cycle arrest in G1-phase, and apoptosis in CCRF-CEM (T-ALL), NALM6 (Bp-ALL), REH (Bp-ALL, TEL/AML1) and SupB15 (Bp-ALL, BCR/ABL) cells. These effects were abolished by treatment with the adenosine kinase inhibitor 5'-iodotubericidin prior to addition of AICAR indicating that AICAR's cytotoxicity is mediated through AMPK activation. Moreover, we determined that growth inhibition exerted by AICAR was associated with activation of p38-MAPK and increased expression of the cell cycle regulators p27 and p53. We also demonstrated that AICAR mediated apoptosis through the mitochondrial pathway as revealed by the release of cytochrome C and cleavage of caspase 9. Additionally, AICAR treatment resulted in phosphorylation of Akt suggesting that activation of the PI3K/Akt pathway may represent a compensatory survival mechanism in response to apoptosis and/or cell cycle arrest. Combined treatment with AICAR and the mTOR inhibitor rapamycin resulted in additive anti-proliferative activity ALL cells. AICAR-mediated AMPK activation was found to be a proficient cytotoxic agent in ALL cells and the mechanism of its anti-proliferative and apoptotic effect appear to be mediated via activation of p38-MAPK pathway, increased expression of cell cycle inhibitory proteins p27 and p53, and downstream effects on the mTOR pathway, hence exhibiting therapeutic potential as a molecular target for the treatment of childhood ALL. Therefore, activation of AMPK by AICAR represents a novel approach to targeted therapy, and suggests a role for AICAR in combination therapy with inhibitors of the PI3K/Akt/mTOR pathways for the treatment of childhood in ALL

Effects of Individual and Work-related Factors on Incidence of Shoulder Pain in a Large Working Population

Objectives: The aim of this study was to assess the effects of individual and work-related factors on the incidence of shoulder pain in a large French working population. Methods: A total of 3,710 workers of a French region were randomly included in a cross-sectional study between 2002 and 2005. They completed a self-administered questionnaire about musculoskeletal symptoms, individual factors and exposure to work constraints. In 2007, 2,332 responded to a follow-up questionnaire. The Nordic questionnaire was used both times to assess shoulder pain during the preceding 7 days. Associations between incident shoulder pain and individual and work-related factors at baseline were studied by multivariate logistic regression for both genders. Results: A total of 946 men and 709 women without shoulder pain at baseline were eligible for the analyses. At follow-up, 105 men (11.1%) and 145 women (20.5%) reported shoulder pain. For men, age (OR 3.3, 95% CI, 1.7–6.5 for ≥50 yr), working with arms above the shoulder (1.5; 1.0–2.3) and high perceived physical exertion (1.6; 1.0–2.5) increased the risk of incident shoulder pain. For women, the factors associated with incident shoulder pain were age (2.9; 1.5–5.8 for ≥50 yr), obesity (2.5; 1.4–4.5), temporary employment (2.1; 1.1–3.7), high perceived physical exertion (2.2; 1.4–3.5) and low decision latitude (1.6; 1.0–2.3). Conclusion: Age was the strongest predictor of incident shoulder pain in both genders. BMI and biomechanical and psychosocial factors were also identified as risk factors, whereas no factor related to work organization remained in the final models

Magnetoconductance anisotropy of a polymer thin film at the onset of metallicity

Thin films of poly(2,5-bis(3-dodecyl-2-yl)-thieno[3,2-b] thiophene) (C12-PBTTT) polymer under electrolyte gating and doping are investigated as model systems for organic thin films devices approaching the metallic side of a metal-insulator (M-I) transition. For the most doped samples, with an estimated density reaching 8 x 10(20) cm(-3) holes and a conductivity exceeding 1000 S cm(-1), a positive high-field magnetoconductance is found in a limited temperature range window and only when the field is perpendicular to the sample plane. This signature of weak localization, combined with indications of finite zero-temperature conductivity, allows us to identify delocalized metallic-like transport in these thin films, even though the conductivity decreases when cooling down the samples

Cluster structures on quantum coordinate rings

We show that the quantum coordinate ring of the unipotent subgroup N(w) of a symmetric Kac-Moody group G associated with a Weyl group element w has the structure of a quantum cluster algebra. This quantum cluster structure arises naturally from a subcategory C_w of the module category of the corresponding preprojective algebra. An important ingredient of the proof is a system of quantum determinantal identities which can be viewed as a q-analogue of a T-system. In case G is a simple algebraic group of type A, D, E, we deduce from these results that the quantum coordinate ring of an open cell of a partial flag variety attached to G also has a cluster structure.Comment: v2: minor corrections. v3: references updated, final version to appear in Selecta Mathematic

Comparison of risk factors for shoulder pain and rotator cuff syndrome in the working population

BACKGROUND: To compare risk factors for shoulder pain without and with rotator cuff syndrome (RCS).METHODS: A total of 3,710 workers of a French region were randomly included in the cross-sectional study between 2002 and 2005. Personal and occupational risk factors were assessed during a physical examination and by a self-administered questionnaire. Multinomial logistic modeling was used for the following outcomes: no shoulder pain and no RCS (reference), shoulder pain without RCS (called "shoulder pain") and RCS, separately for men and women. RESULTS: The prevalence rates of "shoulder pain" for men and women were 28.0% and 31.1%, respectively, and the prevalence rates of RCS were 6.6% and 8.5%, respectively. In men, "shoulder pain" and RCS were associated with age, high-perceived physical exertion, and arm abduction. Automatic work pace and low supervisor support were associated with "shoulder pain," and high psychological demand and low skill discretion with RCS. In women, "shoulder pain" and RCS were associated with age, repetitiveness of tasks, and low supervisor support. High perceived physical exertion and exposure to cold temperatures were associated with "shoulder pain." CONCLUSIONS: Age was more strongly associated with RCS than with shoulder pain without RCS for both genders. Biomechanical and psychosocial factors were associated with "shoulder pain" and RCS and differed between genders